Embedded deep in the constitutional imagination is the notion that courts can implement rights and effectuate the hope of Marbury v. Madison while avoiding running amok and falling into the abyss of Lochner v. New York. This Article challenges this belief and argues that the two cases are not opposites but fraternal twins. In this story, however, Marbury becomes Lochner’s twin not by the use of drugs, which is how Robert Louis Stevenson imagined that Dr. Jekyll became transformed into Mr. Hyde, but by exposing the workings of the constitutional imagination across space and time. The comparative and historical record evinces deep, albeit hidden, linkages between the two cases. Part I of this Article introduces the dichotomy between these two cases and argues that we need to uncover the linkages between them if we are to understand the jumble of ideas that comprise judicial review. Part II of this Article historicizes the relationship between the two cases and argues that Marbury and Lochner became linked in the nineteenth century as judicial review germinated in the constitutional imagination in the United States and abroad. Part III examines how Lochner shaped the political construction of judicial review around the globe in the twentieth century. When the hope of constitutionalized rights (Marbury) traveled abroad, it was joined with the fear that courts might run amok (Lochner). As a consequence, polities abroad adopted different and stronger mechanisms of political accountability than the United States as the price of granting courts the power of constitutional judicial review. Judicial review transformed not only politics but also courts that suddenly had to grapple with the problem of accommodating legislation to constitutional text. Part IV argues that the judicial elaboration of Marbury has had a perverse impact, as courts in civil law jurisdictions have become more like common law courts whereas the United States Supreme Court has become more like a civil law court. Part V concludes that the spread of judicial review is best understood as the story of Lochner, not Marbury, writ large around the globe. In exposing the workings of the constitutional imagination, debates over the fear of power are considerably more illuminating that those surrounding the hope of its exercise.